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Oct. 10, 2011 -- A combination of two drugs -- the chemotherapy drug Fludara and the biologic drug Campath -- may allow people with hard-to-treat chronic lymphocytic leukemia (CLL) to live longer.

One of the most common blood cancers affecting adults in the U.S., CLL is considered incurable. In CLL, there are too many abnormal white blood cells in the blood and bone marrow. About 14,570 new cases of CLL will be diagnosed in the U.S. this year, according to the American Cancer Society. And about 4,380 people will die from the disease.

"There is a tremendous need for new therapies," says Ira Braunschweig, MD, director of the Bone Marrow Transplantation Program at Montefiore Medical Center in the Bronx, N.Y. "This is one of the most common types of leukemia and it is still a deadly disease." Braunschweig reviewed the study for WebMD.

Compared to treatment with Fludara (fludarabine) alone, the new combination increased "progression-free survival" or the length of time in which a person is free from disease after finishing treatment, and prolonged the lives of people who have had a relapse.

The findings are published online in The Lancet Oncology.

How It Works

Chemotherapy drugs like Fludara kill cancer cells. Campath (alemtuzumab) is a monoclonal antibody therapy. It targets a protein called CD52 that is found on the surface of white blood cells. It attaches to the cells and then rallies the immune system to help kill them.

In the study, 168 people with CLL who had relapsed or who did not respond to previous therapy received Fludara plus Campath and 167 received Fludara alone for up to six 28-day cycles. People who received the combination remained progression-free for a median of 23.7 months after treatment (about half remained progression-free for less than 23.7 months, half more), while those who took Fludara alone had a median of 16.5 months of progression-free survival.

The overall survival rate was also higher for people who got both drugs, the study showed. The findings held for older people and people with advanced CLL.

Side effects in both groups included low white blood cell count and an abnormally low number of blood platelets. The risk of serious complications, including infections, was higher in the combination group. That said, a similar number of people from each group stopped treatment because of side effects. In addition, a similar number of people died in both groups.

Researchers say the combination therapy eliminates the need for certain harsh chemotherapy agents used in other combinations. What’s more, the doses required of Fludara plus Campath are lower when the agents are used together. The new combination may also hold a convenience edge. It is given three days per month. The standard treatment is given three times a week for up to 12 weeks.

Treating CLL

"The study shows clear benefits of the combination of Campath and Fludara for relapsed refractory CLL patients," says Hildy Dillon, senior vice president of The Leukemia and Lymphoma Society in White Plains, N.Y.

"Relapsed/refractory or progressive CLL is difficult to control or keep in check, so these results are very encouraging," Dillon says in an email. "It adds another possibility to keep their disease under control and prolong survival."

There is a caveat. "It is not possible to predict in advance which patients will benefit from this combination," she says.

The next step is for people with progressive CLL to ask their oncologists about this combination and whether or not it is an appropriate alternative.

Braunschweig agrees that this combination treatment may have a role in treating CLL. He says that this combination must now be compared to the gold standard, which as of now is a triple combination of Fludara, cyclophosphamide, and Rituxan (rituximab). Cyclophosphamide is a chemotherapy drug. Rituxan is a biologic drug that targets abnormal white blood cells found in people with CLL.

In general, CLL treatment depends on whether or not a person has symptoms, Braunschweig says. Many people who are diagnosed with CLL have no symptoms and are diagnosed based on abnormal blood test results. Others may have general symptoms such as severe fatigue and bleeding.

"If CLL is asymptomatic [without symptoms] and their blood counts look good, we watch and wait," he says. "If someone has symptoms or is profoundly anemic or has low blood platelets, we start chemotherapy.

"Many combination treatments are showing effectiveness and probably the natural history of disease can be impacted, so that is the encouraging message," Braunschweig tells WebMD.

None of these treatments are cures, he says. Bone marrow and stem cell transplants can be curative.

"Because there are no curative therapies for CLL, it's always important to have other options," says Nicole Lamanna, MD, a leukemia specialist at Memorial Sloan-Kettering Cancer Center in New York City.

"Many people with CLL wind up cycling on and off chemotherapy when their disease recurs," says Lamanna, who was not involved in the study. "It is always good to have other combination or salvage regimes to use in this situation."

She tells WebMD that longer follow-up studies are needed, especially when it comes to risks. In addition, fludarabine alone was compared to the combination therapy in this study of people with recurrent or hard-to-treat CLL.

"Fludarabine alone is not usually given as a salvage therapy, so it makes sense that the combination was better," she says.